Conventionally, a vehicle such as an automobile is equipped with a wiper device, which wipes off rainwater, dust, etc. attached on a windshield to ensure the view of a driver. The wiper device is provided with a wiper arm swingably driven by an electric motor, and a wiper blade attached to the wiper arm. The wiper blade is provided with a holder main body rotatably attached to a distal-end side of the wiper arm, and a blade rubber retained by the holder main body. The blade rubber is elastically contacted toward the windshield by the pressing force of the wiper arm and the elastic force of vertebrae, thereby swingably drives the wiper arm by driving an electric motor; as a result, the blade rubber operates reciprocating wiping on the windshield.
As such a wiper blade, for example, the techniques described in WO 2009/153097 has been known. The wiper blade described in WO 2009/153097 is provided with a holder main body (14) retaining a blade rubber (38) with a pair of vertebrae (36). An arm coupling member (50) is connected to the holder main body (14) via a pair of supporting members (22). Therefore, the pressing force of a wiper arm is transmitted to the blade rubber (38) via the arm coupling member (50), the supporting members (22), and the holder main body (14).
The wiping performance of a wiper blade has been improved by integrally providing a fin part receiving travel winds along the longitudinal direction of a wiper blade, thereby imparting downforce (pressing force toward the windshield) to the wiper blade. As a wiper blade having such a fin part, for example, the techniques described in Japanese Patent Publication No. 2007-532380 (FIG. 1) has been known. The wiper blade described in Japanese Patent Publication No. 2007-532380 (FIG. 1) is provided with a blade rubber (bottom-part wiping strip), a flat-plate-like vertebra (longitudinal-direction center element), and a fin part (spoiler) from the windshield (window) side, in order, that is, a triple structure. The vertebra is provided inside a holder main body (center tubular main body), and the fin part is integrally formed with the holder main body.
However, according to the wiper blade described in WO 2009/153097, the height at which the pressing force of the wiper arm acts is higher than the height at which the elastic force of the vertebrae (36) acts, that is, the distance from the windshield to each supporting member (22) is longer than the distance from the windshield to each vertebra (36). Therefore, the pressing force of the wiper arm and the elastic force of the vertebrae (36) are transmitted from different heights to the blade rubber (38), the transmitting directions of the pressing force and the elastic force are varied when the wiper blade carries out reciprocating wiping operation, therefore, and wiping does not uniform without getting stabilization of the wiping performance of the wiper blade.